


Ajin/Undertale Crossover Drabbles and Oneshots

by DragonPrincess101



Category: Undertale (Video Game), 亜人 - 三浦追儺 & 桜井画門 | Ajin - Miura Tsuina & Sakurai Gamon
Genre: Adopted Sibling Relationship, Ajin!Frisk, Ajins and Monsters United, Ambassador Frisk, Chara is a nightmare for Frisk's Enemies, Disapproving Toriel, Drabble, Family Feels, Family Shenanigans, Flirty Frisk, Frisk is a Sweetheart, Frisk is an ajin but if anyone kills them Chara and Flowey will make things HELL FOR FRISK'S enemies, Gender-Neutral Frisk, Goat Mom Is Best Mom, Government Experimentation, Immortality, Kou laughs at Sans's jokes, Magic-Users, Monsters, Non-Chronological, One Shot, Orphan Frisk, Other Additional Tags to Be Added, Post-Undertale Genocide Route, Post-Undertale Pacifist Route, Protect The Children!!!, Protective Chara, Protective Papyrus, Protective Sans, Racism, Sans Makes Puns, Toriel is Very Protective, Unethical Experimentation
Language: English
Status: In-Progress
Published: 2017-03-29
Updated: 2017-03-31
Packaged: 2018-10-12 11:09:09
Rating: Mature
Warnings: Graphic Depictions Of Violence
Chapters: 2
Words: 618
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/10489548
Author URL: https://archiveofourown.org/users/DragonPrincess101/pseuds/DragonPrincess101
Summary: What it says on the title...Also I'm think of making the complete crossover...so this is just a list of idea pieces and oneshots(Warning: NOT IN ORDER)





	1. Meet Flowey part 1 of 2

**Author's Note:**

> I don't own Undertale or Ajin

**Summary for the Chapter:**

> Idea 1: 
> 
> Kei and Kou fell underground on their way to stop Satou. They had an adventure they can't even dream of.

Kei and Kou wake up on the bed of blossoms.

 

Kei and Kou had fallen into the hole while trying to get to a city to stop Satou…

 

“W-what are we?” asked Kou.

 

“I think we are underground...” said Kei looking up and sees a hole above them.

 

The hole is too far up to reach.

 

Kou is pretty upset and then he sees a hall ahead of them. He goes forward. Kei sighed and follows him.

 

“Howdy! I’m Flowey! Flowey the Flowey” said a flower with a face smiley at them

 

Kou screamed while Kei gasped.

  
“Hmm! You two are new to the underground aren’t you?” said Flowey.


	2. Frisk's Big Brothers

**Summary for the Chapter:**

> Idea 2: (this is a oneshot this time)
> 
> After Frisk, Kei, and Kou brings the monsters to the surface. Frisk decide not to run away from the human government anymore... Frisk want humans to accept monster and ajins as equals. Frisk became the ambassador of monsters, and their new big brothers Kei & Kou are their advisors.
> 
> Frisk is trying their best to show the humans that being an ajin or a monster does make them anything less of a person...While the monsters are doing their best to protect Kou, Kei, and Frisk.

**Notes for the Chapter:**

> I kind of want to this this fanfic but there are still other ideas

Frisk had confess to the monsters what they are and why they had run away from humans….Everyone was shock...Kei, Kou, Sans, and Papyrus didn’t seem surprised though.

 

“...That...would explain a-a-a lot” said Alphys in shock and realization.

 

“Your soul did have  **strange black dust** around it...” said Papyrus.

 

“I’m am not surprised” thoughted Sans and he chuckles.

 

“So...it doesn’t matter that I’m a demi-human? Like Kou and Kei” said Frisk in sign language.

 

Everyone looks at them and laughed except Kei.

 

“Frisk, we are all monsters here… the only thing unusual about you is that you look like a plain human” said Undyne.

 

“I love you no matter what or who you are” said Toriel kindly.

 

“But you sure you would be alright we all go to the surface? You did say that the human government are after you and your race…and there is Satou we must worry about...” said Asgore with concern.

 

Frisk suddenly speaks… “I’m done with running now...After what I’ve been through...what we been through… I’m tired of running from my problems now...”

 

“Well said” said Kei.

 

“Don’t worry Frisk, I’ll make sure no one on the surface tries to capture you I promised” said Kou hugging Frisk.

 

Frisk hugs back smiling.

 

“I will protect you my children as well, I won’t let you become experiments...” said Toriel to Kei, Kou and Frisk as she hugged the 3 ajins.

 

“So will I” said Asgore as he hug the ajins as well.

 

“I’ll make sure no one gets you guys and not even these punching bags here too” said Undyne as she grabs Kou and headlocks him and gives him a noogie.

 

“N-not again!” shouted Kou.

 

She lets go of Kou then punches Kei’s arm.

 

“Hey!” shouted Kei rubbing his arm.

 

“I-I don’t know if I could...but I-I-I...I’ll try” said Alphys.

 

“I’ll help you lover” said Undyne as she put her arm over Alphys’s shoulders.

 

“I, the Great Papyrus will protect our new ambassador and their advisors as well!” said Papyrus.

 

Kou smile excitedly while Kei rolled his eyes.

 

“Because the promise I made, that you two laughed at my jokes and that you made some awesome jokes too...I’ll join, Naka-NO one will make labrats out of you” said Sans to Kou and Frisk.

 

Kou laughs and Frisk smiled while Kei sighs when Sans made a pun again.

 

Sans looks at Kei and turns to Kou. “And I’ll keep Mr. Nah-guy safe too, even if he’s such a party pooper...”

 

Kei rolled his eyes when Sans made the pun on his name as well while Kou laughs again.

 

“For the last time! Stop bringing that story up” said Kei blushing.

 

During their adventure, Kei had fell into some monster’s droppings…

 

The rest of the monsters give their support to the three ajins...While Kou and Frisk are very happy right now… Kei is very concern about something... 

  
“ _ **Humans won’t accept ajins**...if they don’t see ajins as people...how could they accept **monsters as people**_?” thought Kei.

**Notes for the Chapter:**

> I like to think that Toriel would be the type who would never forgive the human government for what they did to Kei Nagai...But she's won't hurt any human...unless they tried to take away her children...

**Author's Note:**

> Ok so ajins have it tough in the manga and the show...
> 
> So how would they feel about monsters?
> 
> How would Japan's citizens and government feel about monsters?


End file.
